1. Field of the Invention
The present invention relates generally to surgical devices, and more particularly, to a surgical device for ligating and severing a side branch of a vessel to be harvested.
2. Prior Art
Both saphenous veins and radial arteries are used as conduits in coronary artery bypass surgery. Conventional techniques for harvesting these vessels involve an incision length approximately equal to the length of the vessel being harvested. Recently, various bipolar endoscopic vessel harvesting devices have been developed as a means of removing saphenous veins or radial arteries in a minimally invasive manner.
Users of theses devices frequently struggle to separate side branches of the veins or arteries when said side branches run beneath or above the main trunk of the vessel. In addition, the visualization of the vessel may be lost in excess adipose tissue. Finally, the user friendliness of these devices is subject to question since the steps involved in identifying, securing, and dissection/ligation of side branches is not always intuitive, i.e., the user frequently has to concentrate on what his or her hands are doing and not the vessel at hand. Current bipolar devices also fail to complete the terminal ligation required to excise the vein or artery.
Others have attempted to harvest vessels via endoscopic means by several methods. One method involves use of scissors and ligating clips. Two tools are required for this approach, thus complicating the procedure by excess tool exchanges. Furthermore, the placed clips can hinder subsequent movement of instruments. Finally, foreign bodies (clips) are left in the patient""s limb.
Another approach involves the use of a knife placed between two wire guides that are capable of applying a current across the side branch. This design can potentially result in the spread of thermal energy to the target vessel, potentially compromising its utility as a conduit for CABG surgery. Still yet another approach involves the use of scissor-like clamping jaws that open around a side branch, and then must be closed, whereby a current is applied to the vessel within the jaws before the vessel is harvested. The movement of the jaws is frequently hindered by surrounding tissue or by an endoscopic spoon used to provide visualization.
Therefore it is an object of the present invention to provide a surgical device for endoscopic vessel harvesting which is friendlier to use than conventional endoscopic vessel harvesting devices.
It is another object of the present invention to provide a surgical device for endoscopic vessel harvesting which eliminates the need for ligating clips to ligate side branches of a vessel being harvested.
It is yet another object of the present invention to provide a surgical device for endoscopic vessel harvesting which limits the spread of thermal energy so as not to compromise the utility of the vessel to be harvested.
It is yet another object of the present invention to provide a surgical device for endoscopic vessel harvesting which eliminates the necessity of opening and closing scissor-like jaws around a side branch to ligate the same.
It is still yet another object of the present invention to provide a surgical device for endoscopic vessel harvesting which minimizes the need for multiple instrument exchanges needed to harvest a vessel.
Accordingly, a surgical device is provided. The surgical device comprises: a first shaft having a first projection radially offset from an axial direction of the first shaft, the first projection having a first clamping surface; a second shaft slidably disposed relative to the first shaft, the second shaft having a second projection radially offset from the axial direction, the second projection having a second clamping surface; first actuation means for sliding the second projection relative to the first projection to capture a vessel between the first and second clamping surfaces; at least one electrode for applying cauterizing energy to cauterize the captured vessel; a cutting blade movably disposed on one of the first or second projections; and second actuation means for moving the cutting blade to sever the vessel captured between the first and second projections. Preferably, the vessel captured, cauterized, and severed is a side branch of a blood vessel being harvested.
Preferably, the first and second projections are offset from the axial direction of the first and second shafts, respectively, at an angle of about 90 degrees.
The surgical device preferably further comprises a handle, wherein a proximal end of the first shaft is fixed to the handle and the first actuation means comprises a button movably disposed in the handle, wherein movement of the button slides the second projection relative to the first projection. When so configured, the surgical device preferably further comprises: biasing means for biasing the first and second projections together such that the first and second clamping surfaces are in substantial contact; a control rod operatively connected at a proximal end to the button and at a distal end to the cutting blade, wherein the control rod is disposed in a lumen of the first shaft; wherein the second projection is slid relative to the first projection by actuating the cutting blade to act against the second clamping surface to spread the second and first projections apart.
Preferably, the surgical device further comprises a handle, wherein a proximal end of the first shaft is fixed to the handle, the cutting blade is disposed in the second projection, and the second actuation means comprises a button movably disposed in the handle, wherein movement of the button moves the cutting blade to sever the vessel. When so configured, the surgical device further comprises a control rod operatively connected at a proximal end to the button and at a distal end to the cutting blade, wherein the control rod is disposed in a lumen of the first shaft.
The surgical device also preferably further comprises a dissection means for dissecting tissue from a blood vessel to be harvested. The dissection means preferably comprises a third shaft having an internal lumen for passage of an endoscope therein, the dissection means further having a headpiece shaped for dissecting tissue. When so configured, the surgical device further comprises a handle, wherein the third shaft and the first shaft are arranged parallel and each are connected at a proximal end to the handle.
Preferably, the cauterizing energy is radio-frequency energy supplied to the at least one electrode. Alternatively, the cauterizing energy can be sonic energy supplied to the at least one electrode. The at least one electrode preferably comprises a first electrode of a first polarity and a second electrode of a second polarity opposite from the first polarity, the first electrode being disposed on the first clamping surface and the second electrode being disposed on one of the second clamping surface and cutting blade, preferably, on the cutting blade.
The surgical device also preferably further comprises alignment means for maintaining alignment of the first and second clamping surfaces.
Also provided is a surgical device for endoscopic vein harvesting. The device comprising: a first shaft having a first projection radially offset from an axial direction of the first shaft, the first projection having a first clamping surface; a second shaft slidably disposed relative to the first shaft, the second shaft having a second projection radially offset from the axial direction, the second projection having a second clamping surface; a dissection means for dissecting tissue from a blood vessel to be harvested; first actuation means for sliding the second projection relative to the first projection to capture a side branch of the vessel between the first and second clamping surfaces; at least one electrode for applying cauterizing energy to cauterize the captured side branch; a cutting blade movably disposed on one of the first or second projections; and second actuation means for moving the cutting blade to sever the side branch captured between the first and second projections.
The dissection means of the surgical device for endoscopic vein harvesting preferably comprises a third shaft having an internal lumen for passage of an endoscope therein, the dissection means further having a headpiece shaped for dissecting tissue in proximity to the vessel. When so configured, the surgical device further comprises a handle, wherein the third shaft and the first shaft are arranged parallel and each are connected at a proximal end to the handle.
Still yet provided is a method for severing a side branch of a vessel. The method comprises: providing the surgical device; positioning the surgical instrument over the vessel; positioning the first and second projections around the side branch; sliding the second shaft to capture the side branch between the first and second clamping surfaces; applying a cauterizing energy to the first and second electrodes to cauterize the captured side branch; and moving the cutting blade to sever the side branch captured between the first and second projections.
The sliding step preferably comprises actuating a button movably disposed in a handle on the surgical instrument, wherein actuation of the button slides the second projection relative to the first projection. The moving step preferably comprises actuating a button movably disposed in a handle of the surgical instrument, wherein movement of the button moves the cutting blade to sever the side branch.
The method preferably also further comprises dissecting tissue from around the vessel to expose the side branch. The positioning of the first and second projections around the side branch preferably comprises rotating the surgical instrument about the axial direction.